1. Field of the Invention
The present invention relates to an electric connection box in which cassette-like electric parts can be attached in a module-like manner to side surfaces of a casing. More particularly, the present invention relates to an electric connection box in which cassettes of different sizes and shapes can be fixed to common positions.
The present application is based on Japanese Patent Application No. Hei. 10-39291, which is incorporated herein by reference.
2. Description of the Related Art
Generally, in a recent automobile provided with various electric equipments, there is used an electric connection box by which a plurality of electric circuits are connected together in a concentrated manner so as to transmit signals between the electric equipments.
An electric connection box, shown in FIG. 10, comprises a box-like casing 100 whose interior is divided in longitudinal and transverse directions into a plurality of sections by partition walls 1a, and a plurality of relay cassette fitting portions 2 formed respectively on inner surfaces of the sections, divided by the partition walls 1a, and opposite outer side surfaces of the casing. Each of the cassette fitting portions 2 has a cassette bracket construction for fixedly holding a module-like relay cassette.
In many cases, the number and kind of electric equipments to be mounted varies depending on the kind of a car and even on the grade of the car of the same kind, and therefore because of this variable factor, the casing 100, which is the essential part, is used in common for the various kinds of cars. The required number of cassettes are attached to the casing in accordance with the electric equipments to be used, and by doing so, the required electric equipments are mounted on the car in accordance with the kind and grade of the car. In the illustrated electric connection box, up to 6 cassettes can be attached to the outer side surfaces of the casing if necessary.
Each of the cassette fitting portions 2, formed at the outer side surfaces of the casing 100, includes a pair of vertically-extending partition bars 3 (to be disposed respectively on opposite sides of the cassette) formed on the outer side surface of the casing 100, a pair of fitting guides 4 and 4 which are formed between the pair of partition bars 3 in parallel relation thereto, and have fitting grooves, respectively, for guiding the sliding movement of the cassette, and a lock pawl 5 which is formed between the pair of fitting guides 4 and 4 so as to retain the inserted cassette against withdrawal.
For attaching the cassette, the front end portion of the cassette is inserted into the cassette fitting portion from the lower side of the casing, and then is moved upward along the fitting guides, and when the cassette slides over the lock pawl 5, the cassette is fixed by the lock pawl against withdrawal.
In the casing 100 of the above construction, however, only one kind of cassettes (for example, relay cassettes) can be attached thereto, and cassettes of different sizes and kinds can not be attached to the casing.
And besides, the kinds of cassettes, varied in number depending on the kind and grade of the car, include fuse cassettes in addition to the above relay cassettes, and the fuse cassette and the relay cassette are slightly different in size from each other, and therefore it is necessary to prepare another casing having fitting portions for respectively holding the fuse cassettes. Therefore, there have been encountered drawbacks that the degree of freedom of wiring connection between the casings, as well as the degree of freedom of arrangement of the cassettes, is low, and that the size of the electric connection box is increased.